Establishment and application of a method for determination of trace volatile aroma components in sauce-flavor Baijiu

A method for the determination of trace volatile aroma components in sauce-flavor (Jiangxiangxing) Baijiu was developed by dispersed liquid- liquid microextraction (DLLME) combined with gas chromatography-mass spectrometry (GC-MS). The trace volatile aroma components in the sauce- flavor Baijiu samples from Renhuai and Xishui producing areas were detected, and cluster analysis and partial least squares-discriminant analysis (PLS-DA) were carried out based on the detection results. The results showed that the DB-FFAP capillary column (60 m×0.25 mm×0.25 μm) was adopted, and extraction for 2 min with ether/n-hexane (1∶1) as the extractant. Under these conditions, 59 trace volatile aroma components in sauce-flavor Baijiu could be qualitatively and quantitatively determined effectively, and each component showed a good linear relationship within the detection range. The correlation coefficient (R²) of this method was 0.996 3-0.999 9, the detection limit was 0.15-2.43 μg/L, the quantification limit was 0.28-6.07 μg/L, the spiked recovery rates were 93.00%-103.94%, and the relative standard deviation (RSD) of precision tests (n=6) was 0.34%-6.30%, which indicated that the precision and recovery rates of this method were good and could meet the detection requirements of 59 trace volatile aroma components in sauce-flavor Baijiu. The sauce-flavor Baijiu samples from Renhuai and Xishui producing areas could be effectively distinguished according to 59 trace volatile aroma components. 8 kinds of main difference trace aroma components such as dimethyl disulfide and trimethyl pyrazine, could be screened according to variable importance in the projection (VIP) value>1.